This guide will show you how to run/play "Rogue Lords" on Steam with custom Proton engine.
Make sure you installed Steam from Steam homepage and not from store as a flatpak/Snap package.
Open the terminal and type;
sudo apt install steam
This will download & install the latest version of Steam. Make sure you don't has Flatpak version of Steam as it will only give you trouble getting Proton to work.
Login to Steam and go to Steam tab --> Settings. Activate Steam Play.
Next thing is to install a specific version of Proton GE that work best for Rogue Lords. In terminal type (copy/paste);
cd Downloads wget https://github.com/GloriousEggroll/proton-ge-custom/releases/download/6.21-GE-2/Proton-6.21-GE-2.tar.gz mkdir -p ~/.steam/root/compatibilitytools.d/ tar -xf Proton-6.21-GE-2.tar.gz mv Proton-6.21-GE-2 ~/.steam/root/compatibilitytools.d/
- Now go to your Steam Library and right click on Rogue Lords and click Properties.
- Go to Compatible tab and click Force the use of specific Steam Play etc. and thereafter choose Proton GE 6.21-GE-2